Since you're afraid that the 210mm lens is too short for your purposes, the next steps up are 240mm and 300mm. I don't suppose there's any chance that you could rent or borrow a 300 for a week? That should give you a chance to see if a longer lens is really what you want, before committing your money to a purchase. Certainly with your camera the necessary bellows extension for the 300 is no problem. You might even find yourself wishing for a 360--there's no accounting for personal taste, and you might prefer the increased compression. So trying out a 300 sounds like a logical course of action to me. I certainly wouldn't recommend buying a bunch of lenses which are close to your 210, which you already have--I don't know why some people in this thread have recommended it.

I always found the 210mm lens either too short or too long. I use a 180 as a normal and a 270mm f9 Apo Artar as my portrait lens. It's sharp though, so if you want a soft focus lens, it's not the one to choose.

I would go with the 210mm, it should work fine. I prefer a slightly wider lens to include more of the enviroment/subject (135mm for the linked photo). The important thing to remember is to not waste to much time obsessed with slight differences in focal length, just go out and make lots of photos with the equipment you have, thats the best solution.

A 210 can work for portraits, but with tighter than head and shoulders, some people will want a longer lens. My favorite by far for 4x5 portraits is the Fujinon 250 soft focus, you can do anything with it in terms of sharp to very soft and once you get the hang of it, the results are stunning. I know it seems like the difference between 210 and 250 wouldn't be that much, but to me, there is a meaningful difference, especially when you get closer to the subject. Go ahead and experiment some with the 210 and see what you think, if you are satisfied no need to look further.
Good luck
Doug Webb

The difference between a 250 and 210 makes a difference,
210 is just too short. 300 is too long.

Mr. Cardwell as always is the voice of
reason here. For once, though, I would
disagree with him only in his opinion
that 300 is too long. I use a 12-inch
Commercial Ektar on my Sinar Norma
for most of my work in 4x5 and 5x7
and I find it to be the ideal length for
my purposes. I'm attaching a close
headshot with the 12-inch CE on 4x5
for reference.